[MarkusV]

Das schreibt das 737-400 Manual von Boeing dazu:

"Map Center Label (<CTR>)

Identifies the waypoint around which the map display is centered.

Whenever the EFIS mode selector is positioned to PLAN, the label is automatically displayed for the first geographically fixed waypoint on the displayed page."

Und die Taste 6R ist wie folgt beschrieben:

"Map Center Step (MAP CTR STEP)

Displayed on the CDU when PLAN is selected on the associated EFIS control panel. Replaces the EXTENDED DATA or the ACTIVATE PROMPT.

Push - advances the <CTR> Label on the CDU to the next geographically fixed waypoint in the route and moves the respective waypoint to the center of the HSI."